[doppler (Rick)]

I think these are the key words here, "made it difficult to reliably get good long subs (>5mins)." Difficult to set up but not impossible, it's just a lot easier with a lightweight system. Off course the whole purpose of using a fat fast newt is not having to use long subs. I have just finished setting up a 10" f5 newt on a HEQ5 pro mount (on an in ground pier) and it is guiding well with a 50mm finder guider. This set up is about 15 kgs, apparently a couple of kgs over according to some specs. There are a few others here that are also successfully imaging with maxed out mounts.